Overthrow guard for knitting instruments



J. F. WILCOMB.

OVEHTHROW GUARD FOR KNITTING INSTRUMENTS. APPLICATION FILED MAY 24, 1920.

1,403,931 Patented Jan. 17, 1922.

2 SHEETSSHEET I.

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Jfiank Mlzlcom,

J. F. WILCOMB.

OVEHTHROW GUARD FOR KNITTING INSTRUMENTS.

APPLICATION FILED MAY 24, 1920.

Patented Jan. 17, 1922.

2 SHthIS-SHEET 2.

Inventor:

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UNITED STATES PATENT oFFicE.

J. FRANK WILCOMB, OF WORCESTER, MASSACHUSETTS, ASSIGNOR T0 SPARTAN NEEDLE COMPANY, OF PROVIDENCE, RHODE ISLAND, A CORPORATION OF RHODE ISLAND.

Specification of Letters Patent.

Patented Jan. 17, 1922.

application filed May 24, 1920. Serial No. 383,839.

To all whom it may concern:

Be it known that I, J. FRANK WILcoMB, a citizen of the United States, and a resident of Worcester, Massachusetts, have invented certainnew and useful Improvements in Overthrow Guards for Knitting Instruments, of which the following is a specification.

This application is a division in part and a. continuation in part of that filed by me in the United States Patent Office April 12, 1919, No. 289,691.

The invention relates to means for preventing overthrow of the knitting instruments of a knitting machine, such as the needles or sinkers, and it consists in the features and combination and arrangement of parts hereinafter described and particularly pointed out in the claims.

In the accompanying drawings Figure 1 is a part sectional view and part side elevation of one type of knitting machine embodying the invention, this being representative of any knitting organization to which my invention is applicable.

Fig. 2 is a view, in the nature of a diagram, of the cams for the needles and cams for the overthrow'guards, this figurealso being presented as illustrative of one application of the invention and not as lim1ting the scope of my invention to its combination with the parts shown.

Fig. 3 is an edge view of one form of overthrow guard embodying my invention.

Fig. 4 is a perspective view of the overthrow guard.

. Fig. 5 is a view of a sinker with an overthrow guard for limiting both its forward and its backward stroke.

This application being in part a division of that filed by me in the United States Patent O'fiice as above stated, I have shown herein the same kind of two-part needle as that disclosed in said application, oonsisting of a hooked yarn drawing element 1 and a loop -spreadingand hook guarding element 2, in the form of a quill, the former having a butt 5 and the latter a butt 14, to travel in the cam grooves 24 and 25 respectively, of the cam ring, to be operated thereby for the formation of the loops in knitting, but it 'will be understood. that the overthrow jack or guards will operate with ordinary forms of needles (as well as with other knitting instruments) and it will therefore be understood that the showing of the two-part needle is not to be regarded as limiting my invention in any way.

The knitting instrument carrier may be of any ordinary kind, slotted to receive the needles or other instruments. The knitting instruments, preferably, have no bends or friction devices thereon.

For convenience of description I will refer to the invention, first, in connection with the needle shown in my prior application.

In the same groove with the needle, but below it, is a guard 26 having a spring stem or tail 26", bent sufficiently to cause the guard to have frictional engagement-with the two sides of the needle slot. This friction overthrow guard has a butt 26. A cam 27", providing a very low angled cam path 26, is used for raising the friction overthrow guard upward toward the elevated needle a very short distance.

There is no down throw cam required for this guard. When the guard is forced upward any desired distance, say 1 g of an inch, it will remain in this position until pressed downward again by the needle, on its retracting stroke, coming in contact therewith.

The needles are advanced and retracted in the customary way by cams and as before stated the needle has preferably no restriction or friction bends in it.

As the needle retires downward to draw its loop, the speed or velocity of the needle, due to the steep angle of the stitch cam, is very great, and without some restraint the needle generally overshoots the lower point of the stitch cam, the drag of the yarrr not being suflicient to prevent this. With my improvement, however, the friction guard having been advanced in the needle groove to a position higher than the lowermost movement of the needle, it is obvious that the needle on its retracting or downward stroke will come in contact with the guard just a little before it reaches its extreme retracted position, and the friction guard will be moved downward by the needle, both now being under restraint because of the friction bend of the guard working on the wall of the needle slot. Enough friction is applied to the guard to efiectually her overthrow movement.

throw of the needle, which otherwise would take place.

When the needle has reached its lowestpoint it rises again in the usual way by the action of the cams 24, without having any special restraint exercised thereon, because on its upstroke the needle is free to move away from the guard, and this freedom of action continues until the needle has retracted to near its lowest point again, where it contacts with the friction guard, and thereby is prevented from having over- After the needle has forced the guard downward the guard may remain in that position for any desired part of the stroke or movement of the needle cams. The cam 27* for raising this friction guard may be, as stated above, a very low angled cam. In the present case the cam inclines about 5 from a horizontal line and p the guard may be raised to a needle contacting position during any part of the time preceding the next downward movement of the needle.

By this overthrow guard the only wear or upsetting action that occurs takes place on the end of-the needle and the end of the particular friction guard which is individual thereto, where the needle contacts therewith, and it is obvious that the wear and upsetting effect is only that due to the. needle delivering a single blow to its own guard at each course of knitting, instead. as in ordinary practice, of delivering a blow from each needle of the series to a guard cam common to them all. Furthermore, this upsetting eifect is rendered practically negligible, because the needle does not strike an unyielding surface but one which yields under the impact of the end of the needle.

It will be clear also that the wear and upsetting effect is neutralized or compensated for automatically. The cam which raises the friction guard will raise it, say of an inch or more and if the wear or upsetting efi'ect has shortened the guard and the needle stem by 3 2- cf an inch there is still of an inch margin left for movement of the guard by the needle contacting it in the final part of the downward movement of the needle and overthrow of the needle will be barred just as effectually as if there had been no wear on the needle or guard. In the case however of an ordinary fixed overthrow guard cam or plate, wear or upsetting to any degree will permit the needle to overthrow to exactly the extent of the reduction of the contacting surface due to wear.

A plate or guard cam of the common fixed construction would receive 71500 blows on one spot thereof in a machine having 260 needles and runnin at 275 revolutions per minute, and the or inary overthrow guard device must be reset by hand to compensate for the wear- The overthrow friction guard herein described, being an instrument individual to one needle or other knitting instrumentality, receives but 275 blows per minute and the wear and upsetting effect, therefore, is greatly reduced or practically eliminated, but whatever wear occurs is automatically compensated for, as above described.

I have referred to this guard as being constructed and operated to serve as a needle overthrow guard but it is obvious that in addition to functioning as a needle overthrow guard, it may be used for any of the purposes that jacks heretofore have been used for. It is common to put an auxiliary jack in the needle groove below the needle, also to provide spring bends and tails on the auxiliary jack but the jacks heretofore provided have been used in all cases as needle operating jacks to direct the needle for some special knitting operation and in no case, so far as I know, has a. friction guard been operative to guard the needle against overthrow at the stitch cam. The present form of guard lends itself to any of the urposes for which a jack heretofore has en used and in addition to these uses, by the construction and arrangement herein shown, it becomes a needle overthrow guard element and is novel in the art in this respect.

In Fig. 5, I show an overthrow guard 26', to prevent overthrow of a sinker on its retracting stroke, the sinker being shown at A, and at 26, I show a guard to prevent overthrow of the sinker on its forward stroke. These guards in form are substantially the same as that above described and they are operated and function in substantially the way reviously explained.

The above escription, taken with the drawing, is to be re arded as setting forth one form of physical embodiment of my invention and is therefore presented in an illustrative and not a restrictive sense, it being possible to embody the invention in forms other than that shown.

What I claim is 1. In combination in a knittin machine, a bed having slots for the knitting instruments, knitting instruments in the slots, means for operating the instruments, and elements in the slots, and movable under restraint. said elements being individual to the knitting instruments, tobe struck thereby and by their resistance prevent overthrow of the knitting instruments and means to return the elements to the positions from which 'they were moved by the knitting instruments contacting therewith.

2. In combination in a knitting machine, a bed having slots, knitting instruments slid able in the slots, means for operatin the knitting instruments, elements. also s11 able in the slots of the bed, but under greater restraint than the knitting instruments, said elements being struck. by the knitt ng nstruments, and by their resistance preventing overthrow thereof, and means for restoring the elements to the positions from which they were moved by the knitting instruments.

3. In a knitting machine, the combination of a slotted bed, knitting instruments working in the slots, elements in the slots, individual to the said instruments, and movable under frictional restraint when struck by the knitting instruments, to prevent overthrow of the knitting instruments, and means vfor restoring said elements into positionto be struck by the knitting instruments in the final part of the stroke thereof.

4. In combination in a knitting machine,

a slotted bed, knitting instruments working in the slots, overthrow guards in the slots, individual to the knitting instruments, restrained irom free movement by frictional engagement with thewalls of the slots, but moved when struck by the knitting instruments in the final part of their strokes, and means for restorin the overthrow-guards to their former positions after being moved therefrom by the knitting instruments.

' 5. In a knitting machine, the combination of a carrier having grooves for the knitting instruments, independently operated knitting instruments, inde endently operable overthrow guards mova le under restraint, one for each knitting instrument arranged in the grooves, said knitting instruments being adapted to contact the overthrow guards and retract them in their grooves, and cam means for advancing the overthrow guards.

6. In a knitting machine, the combination of an overthrow guard implement for a knitting instrument, consisting of a slidable element, in the groove with the knitting instrument, said implement being spring pressed against the two sides of the needle groove, a cam for operating the overthrow guard implement in one direction independently of the knitting instrument, said overthrow guard implement being operated in the other direction by the knitting instrument contacting it.

7. In a knitting machine, a carrierhaving grooves for the knitting instruments, overthrow guards and means for independently advancing the overthrow guards and said knitting instruments, said overthrow guards being movable under restraint and being retracted only by the knitting instruments contacting therewith, whereby they serve to prevent overthrow of the said knitting instruments.

8. In combination in a knitting machine, a bed or support having slots, a series of movable knitting implements therein, operating means for said implements, a corresponding series of overthrow guard jacks 26 movable under restraint in said slots and adapted to be struck by said knitting implements and by their resistance substantially to prevent or reduce overthrow thereof, together with means including the cam 26' to return said guard jacks substantially to the position from which they were moved by the impact of said knitting implements.

9. In combination in a knitting machine, a bed or support having slots, a series of movable knitting implements therein, operating means for said implements including a cam groove 25, means movable under restraint and distinct from said operating means and adaptedto receive the impact of said knitting implements, and means including the cam 26 to return said impact receivin means to the position from which they were moved by the impact of said knitting implements.

10. In combination, in a knitting machine, a needle carrier having slots for the knitting needles, knitting needles in said slots, means for operating said needles, elements in said slots and movable under restraint, said elements being individual to the said knitting needles, to be struck thereby and by their resistance prevent overthrow of the knitting needles, and means to return the said elements to the positions from which they weremoved by the knitting needles contacting therewith.

In testimony whereof, I afiix my signature.

J. FRANK WILCOMB. 

